Respiratory biofeedback for radiotherapy

Abstract

A medical system (100, 500) is disclosed that includes a radiation therapy system (102) configured to controllably irradiate a target volume (114) within an irradiation zone (112), an object support (120) configured to support at least a ventral region (124) of an object (122) within the irradiation zone, a respiratory monitoring system (132, 132') configured to provide a motion signal (154, 158) descriptive of respiratory motion of the object, and an object display (130, 130') configured to display a respiratory phase indicator (160, 160') to the object when supported by the object support, execution of machine executable instructions (150) cause a processor (142) controlling the medical system to receive (200) a time resolved magnetic resonance imaging dataset (152) synchronized to a measured motion signal (154). Execution of the machine executable instructions further cause the processor to repeatedly determine (202) a desired motion signal (156) by stepping through the measured motion signal in time, acquire (204) a current motion signal (158) with the respiratory monitoring system, present (206) a respiratory phase indicator on a display, wherein the respiratory phase indicator is configured to indicate a difference (700) between the desired motion signal and the measured motion signal, and generate (208) a control command (162) configured to control targeting of the radiation therapy system using a first portion of the time resolved magnetic resonance imaging dataset synchronized to the desired motion signal or a second portion of the time resolved magnetic resonance imaging dataset referenced by the current motion signal.

Description

Technical Field

[0001] This invention relates to radiotherapy, and more particularly to guiding radiotherapy using magnetic resonance imaging. Background Technology

[0002] As part of the process of generating images of a patient's body, magnetic resonance imaging (MRI) scanners use large static magnetic fields to align the nuclear spins of atoms. Such medical images can be used to plan and / or guide radiation therapy systems.

[0003] To et al.'s journal article "Impact of incorporating visual biofeedback in 4D MRI," J. Applied Clinical Med. Phys., Vol. 17, pp. 128-137 (2016). https: / / doi.org / 10.1120 / jacmp.v17i3.6017 Precision radiotherapy (RT) for abdominal lesions has been complicated by respiratory motion and poor soft tissue contrast in 4D CT. While longer scan times and irregular breathing patterns can be limiting, 4D MRI offers better contrast. To address this issue, visual biofeedback (VBF) has been introduced into 4D MRI. Summary of the Invention

[0004] The present invention provides a medical system, a computer program product, and a method in the independent claims. Embodiments are given in the dependent claims.

[0005] The embodiments can provide a means of guiding improvements to a radiotherapy system using previously acquired magnetic resonance imaging (MRI) datasets. This can be achieved by using a time-resolved MRI dataset (4D MRI dataset) that is referenced or synchronized to a respiratory monitoring system to measure motion signals. During radiotherapy, the current motion signal is measured using the respiratory monitoring system. A display provides a presentation of a respiratory phase indicator. The respiratory phase indicator shows the difference between the desired motion signal and the current motion signal. The respiratory phase indicator provides a biofeedback signal that the subject can use to better control and match the breathing pattern exhibited by the subject when the time-resolved MRI dataset was acquired.

[0006] In one aspect, the present invention provides a medical system comprising a radiotherapy system configured to controllably irradiate a target volume within an irradiation zone. As used herein, an irradiation zone refers to a volume in space, to which the radiotherapy system can redirect or focus the target volume. The medical system also includes an object support configured to support at least a ventral region of an object within the irradiation zone. The ventral region may include the abdomen and / or chest region of the object.

[0007] The medical system also includes a respiratory monitoring system configured to provide motion signals describing the respiratory movements of the object. The respiratory monitoring system can be any system capable of measuring the motion of the object as it breathes. For example, the motion signals can provide the respiratory phase of the object. The medical system also includes an object display configured to display a respiratory phase indicator to the object, which is supported by an object support. As used herein, a respiratory phase indicator can be an indicator presented on the object display and conveying the current respiratory phase or motion of the object.

[0008] The medical system also includes a memory storing machine-executable instructions. The medical system further includes a processor configured to control the medical instruments. The execution of the machine-executable instructions causes the processor to receive a time-resolved magnetic resonance imaging (MRI) dataset. In one example, the time-resolved MRI dataset may be a series of MRI images. In another example, the time-resolved MRI dataset may be an average of images over a specific time period or respiratory phase range.

[0009] In another example, the time-resolved magnetic resonance imaging (MRI) dataset is MRI data that has been preprocessed to indicate the location of various anatomical structures of the object as a function of time or respiratory phase. The time-resolved MRI dataset is synchronized with a measured motion signal. The measured motion signal is periodic in time. The measured motion signal can be equivalent to the motion signal that can be provided by a respiratory monitoring system. The time-resolved MRI dataset thus provides time-resolved MRI data as a function of motion signal.

[0010] The execution of machine-executable instructions also enables the processor to repeatedly determine the desired motion signal by stepping through the measured motion signal in time. For example, the measured motion signal may have a specific waveform or structure that is a function of time or period. The desired motion signal can be acquired from the measured motion signal by dividing the measured motion signal into discrete time intervals or blocks and then sequentially recalling them. The execution of machine-executable instructions also enables the processor to repeatedly acquire the current motion signal using a respiratory monitoring system. The current motion signal may be the motion signal measured at the current point in time.

[0011] The execution of the machine-executable instructions also causes the processor to repeatedly display a respiratory phase indicator on the display. The respiratory phase indicator is configured to indicate the difference between the desired motion signal and the measured motion signal, thus providing a biofeedback signal to the subject and indicating the difference between the desired breathing pattern and the current breathing pattern. The execution of the machine-executable instructions also causes the processor to repeatedly generate control commands configured to control the targeting of the radiotherapy system using either a first portion of a time-resolved magnetic resonance imaging (MRI) dataset synchronized with the desired motion signal or a second portion of a time-resolved MRI dataset referenced to the current motion signal.

[0012] Control commands are generated to match one of two groups in a time-resolved magnetic resonance imaging (MRI) dataset. The first group corresponds to the current desired motion signal. However, if the object deviates too much from the desired motion signal, using that signal to target or control the radiotherapy system would be inaccurate. In this case, the current motion signal is then used to reference the time-resolved MRI dataset and data is obtained that can be used to correctly target the radiotherapy system.

[0013] In this embodiment, data from previous magnetic resonance imaging (MRI) scans are provided in the form of a time-resolved MRI dataset, referenced by measured motion signals. The display of a respiratory phase indicator helps the subject match the breathing pattern used to acquire the time-resolved MRI dataset. If the subject follows the same breathing pattern, then using the time-resolved MRI dataset to predict the future position of the subject's various internal organs is highly accurate. On the other hand, if the subject has an unstable breathing pattern, it is difficult to accurately predict how the subject will move in the future. Therefore, this embodiment can provide improved targeting within the subject for the radiotherapy system.

[0014] In another embodiment, the time-resolved magnetic resonance imaging dataset describes at least one ventral region of the object supported within the irradiation area.

[0015] In another embodiment, the control command is configured to select between a first portion and a second portion of a time-resolved magnetic resonance imaging (MRI) dataset by applying predetermined criteria to the matching between the current motion signal and the measured motion. For example, if the deviation between the current motion signal and the measured motion signal exceeds the predetermined criteria, the system can switch to the second portion of the time-resolved MRI dataset. The second portion of the time-resolved MRI dataset can, for example, be selected as a time offset such that the current motion signal again matches the measured motion signal within the predetermined criteria.

[0016] The term "synchronized to" can indicate that the current motion signal is synchronized or locked to the desired motion signal. The term "referenced to" can also indicate that the current motion signal is synchronized or locked to the desired motion signal with a time or phase offset.

[0017] The motion signal is a signal measured by a respiratory monitoring system. The expected motion signal is a motion signal derived from the motion signal measured by the respiratory monitoring system. The term "expected" is a label used to indicate a specific motion signal. The current motion signal is also a motion signal measured by the respiratory monitoring system. The term "current" is a label that indicates a specific data point measured by the respiratory monitoring system.

[0018] In another embodiment, the medical system further includes a magnetic resonance imaging (MRI) system. The MRI system may be a separate, stand-alone MRI system, or it may be integrated into a radiotherapy system.

[0019] The memory also contains calibration pulse sequence commands configured to acquire calibration magnetic resonance data from the imaging region according to a four-dimensional magnetic resonance imaging protocol. The four-dimensional magnetic resonance imaging protocol described herein includes a magnetic resonance imaging protocol that acquires three-dimensional data spatially and an additional dimension temporally; therefore, the four-dimensional magnetic resonance imaging protocol acquires three-dimensional magnetic resonance imaging data as a function of time.

[0020] The execution of the machine-executable instructions also causes the processor to acquire measured motion signals using a respiratory monitoring system over a predetermined duration. For example, an object can be inserted into a magnetic resonance imaging (MRI) system, and the respiratory monitoring system can be used to monitor the object's breathing. The execution of the machine-executable instructions also causes the processor to control the MRI system to acquire calibration MRI data using the calibration pulse sequence commands. The calibration MRI data is divided into motion phase bins. Measured motion signals can, for example, be used to divide the acquired data into motion phase bins. The execution of the machine-executable instructions also causes the processor to reconstruct a time-resolved MRI dataset based on the calibration MRI data.

[0021] The execution of machine-executable instructions also causes the processor to repeatedly perform the following operations during the acquisition of calibrated MRI data: determining the temporally desired motion signal by time-stepping the measured motion signal; acquiring the calibrated motion signal using a respiratory monitoring system; binning the MRI data into motion phase bins and using the calibrated motion signal; and finally, presenting a respiratory phase indicator on the display. The respiratory phase indicator is again configured to indicate the difference between the provisional motion signal and the calibrated motion signal. In this embodiment, feedback is provided to the subject in the same manner as during its major radiotherapy steps. This can be beneficial because the quality of the MRI data will improve if the subject is able to control his or her breathing more regularly, as the subject's motion is more repeatable.

[0022] If the same type of patient motion monitoring and biofeedback is provided during both the MRI and radiotherapy phases, the quality of time-resolved MRI data will be improved, and the radiotherapy system will be more accurately targeted.

[0023] In another embodiment, the magnetic resonance imaging (MRI) system is integrated into the radiotherapy system. The irradiation zone is within the imaging zone. The result of the irradiation zone being within the imaging zone is that the MRI system can be used to guide or target the radiotherapy system. In this case, the object display and respiratory monitoring system of the radiotherapy system and the MRI system can be the same.

[0024] In another embodiment, the memory also contains imaging pulse sequence commands. The execution of the machine-executable instructions further enables the processor to acquire imaging magnetic resonance data by controlling the magnetic resonance imaging system using the imaging pulse sequence commands during the generation of control commands. The execution of the machine-executable instructions also causes the processor to reconstruct a magnetic resonance image based on the imaging magnetic resonance data. The respiratory phase indicator is fully configured to display at least one magnetic resonance image. For example, the respiratory phase indicator can display the actual magnetic resonance image to the subject to help the subject control his or her breathing pattern.

[0025] In another embodiment, the irradiation zone and the imaging zone are separate. The consequence of this is that the MRI system cannot be used to directly guide the radiotherapy system. In this case, the radiotherapy system can be in one location, while the MRI system can be in a different location. For example, the object can first be placed in the MRI system to provide a time-resolved MRI dataset and measured motion signals. The object can then be physically moved to the radiotherapy system. This can have the advantage of combining the MRI system and the radiotherapy system into a single medical system that works collaboratively. In this example, the radiotherapy system can have a first respiratory monitoring system and a first object display, and the MRI system can have a second respiratory monitoring system and a second object display.

[0026] In another embodiment, the respiratory phase indicator is configured to display the desired motion signal as a waveform. The respiratory phase indicator is fully configured to display the current motion signal as its position relative to the waveform. For example, there might be a cursor indicating the subject's current respiratory phase and comparing it to the desired motion signal. This can help indicate to the subject whether they have the correct respiratory phase. The waveform can also display the maximum and minimum respiratory phases. This can help signal the subject if they are hyperventilating or breathing more heavily than when the motion signal was acquired and measured.

[0027] In another embodiment, the breathing phase indicator is configured to display the desired motion signal as the location of a first object. The breathing phase indicator is also configured to display the current motion signal as the location of a second object. For example, they might be two circles or other geometric shapes. An object might more easily attempt to adjust his or her breathing pattern so that the two objects overlap or are within an acceptable distance of each other.

[0028] In another embodiment, the breathing phase indicator is configured to control the animation of an object using a designed motion signal and the current motion signal. For example, the animation could be a simplified or rendered representation of the object's position or an animation of a person breathing. This can be useful when the object is mirrored and a motion signal is expected.

[0029] In another embodiment, the execution of machine-executable instructions also enables the processor to control the radiotherapy system using control commands. This can be beneficial because it can provide radiotherapy treatments with improved accuracy and effectiveness.

[0030] In another embodiment, the respiratory monitoring system includes a breathing belt.

[0031] In another embodiment, the respiratory monitoring system includes an optical respiratory detection system. This could be, for example, a camera or imaging system.

[0032] In another embodiment, the breathing monitoring system includes an infrared breathing detection system. This could be, for example, an infrared camera system. Infrared breathing detection systems can be particularly effective because they may be able to see through clothing or other garments worn by the subject. An example of a commercially available infrared camera system is the Philips VitalEye system. VitalEye technology and algorithms process more than 200 body positions simultaneously and extract breathing signs.

[0033] In another embodiment, the respiratory monitoring system includes an internal navigation pulse sequence. For example, there may be a magnetic resonance imaging navigation pulse sequence for monitoring matters such as diaphragm position.

[0034] In another embodiment, the display is a projector configured to project a breathing phase indicator onto a wall.

[0035] In another embodiment, the display is a projector configured to project a respiratory phase indicator onto an aperture in the medical system. For example, if the system provides a magnetic resonance imaging system, there may be a projection of the interior of the chest that the object can see.

[0036] In another embodiment, the display is an LCD display.

[0037] In another embodiment, the display is a magnetic resonance imaging-compatible display. For example, a light tube or other technology can be used to move the indicator or display so that it becomes visible to the object.

[0038] In another embodiment, the radiotherapy system is a linear accelerator (LINAC) radiotherapy system.

[0039] In another embodiment, the radiotherapy system is a cobalt radiotherapy system. For example, there may be a cobalt radiation source for providing gamma radiation to irradiate the subject.

[0040] In another embodiment, the radiotherapy system is an X-ray radiotherapy system. For example, an X-ray system can be used to provide radiation for radiotherapy.

[0041] In another aspect, the present invention provides a method of operating a medical system. The medical system includes a radiotherapy system configured to control the irradiation of a target volume within a radiation zone. The medical system also includes a subject support configured to support at least a ventral region of the subject within the radiation zone. The medical system further includes a respiratory monitoring system configured to provide motion signals describing the respiratory movements of the subject.

[0042] The medical system also includes an object display configured to show a respiratory phase indicator to an object supported by an object support.

[0043] The method includes receiving a time-resolved magnetic resonance imaging (MRI) dataset. The time-resolved MRI dataset is synchronized to a measured motion signal. The measured motion signal is periodic in time. The method further includes repeatedly determining a desired motion signal by stepping the measured motion signal in time. The method also includes repeatedly acquiring the current motion signal using a respiratory monitoring system. The method further includes presenting a respiratory phase indicator on a display. The respiratory phase indicator is configured to indicate the difference between the desired motion signal and the measured motion signal.

[0044] The method further includes repeatedly generating control commands configured to control the targeting of the radiotherapy system using a first portion of a time-resolved magnetic resonance imaging dataset synchronized with a desired motion signal or a second portion of a time-resolved magnetic resonance imaging dataset referenced by the current motion signal.

[0045] In another aspect, the present invention provides a computer program product including machine-executable instructions for execution by a processor controlling a medical system. The medical system includes a radiotherapy system configured to controllably irradiate a target volume within an irradiation zone. The medical system also includes an object support configured to support at least a ventral region of an object within the irradiation zone. The medical system further includes a respiratory monitoring system configured to provide motion signals describing the respiratory movements of the object. The medical system also includes an object display configured to display a respiratory phase indicator to the object supported by the object support.

[0046] The execution of the machine-executable instructions causes the processor to receive a time-resolved magnetic resonance imaging (MRI) dataset. This time-resolved MRI dataset is synchronized with measured motion signals. The measured motion signals are periodic in time. The execution of the machine-executable instructions also causes the processor to repeatedly determine the desired motion signal by stepping through the measured motion signals in time. The execution of the machine-executable instructions further causes the processor to repeatedly acquire the current motion signal using a respiratory monitoring system.

[0047] The execution of the machine-executable instructions also causes the processor to repeatedly display a respiratory phase indicator on the display. The respiratory phase indicator is configured to indicate the difference between the desired motion signal and the measured motion signal. The execution of the machine-executable instructions also causes the processor to repeatedly generate control commands configured to control the targeting of the radiotherapy system using either a first portion of a time-resolved magnetic resonance imaging (MRI) dataset synchronized with the desired motion signal or a second portion of a time-resolved MRI dataset referenced by the current motion signal.

[0048] It should be understood that one or more of the foregoing embodiments of the present invention may be combined, as long as the combined embodiments are not mutually exclusive.

[0049] As those skilled in the art will recognize, several aspects of the invention can be implemented as apparatus, method, or computer program product. Therefore, aspects of the invention can take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects, which can be collectively referred to herein as “circuit,” “module,” or “system.” Furthermore, aspects of the invention can take the form of computer program products implemented in one or more computer-readable media having computer-executable code implemented thereon.

[0050] Any combination of one or more computer-readable media can be used. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. As used herein, "computer-readable storage medium" includes any tangible storage medium that can store instructions executable by a processor of a computing device. The computer-readable storage medium may be referred to as a "computer-readable non-transient storage medium." The computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, the computer-readable storage medium may also be able to store data accessible by the processor of the computing device. Examples of computer-readable storage media include, but are not limited to: floppy disks, magnetic hard disk drives, solid-state drives, flash memory, USB thumb drives, random access memory (RAM), read-only memory (ROM), optical disks, magneto-optical disks, and processor register files. Examples of optical disks include compact optical disks (CDs) and digital multi-purpose optical disks (DVDs), such as CD-ROMs, CD-RWs, CD-Rs, DVD-ROMs, DVD-RWs, or DVD-R discs. The term computer-readable storage medium also refers to various types of recording media accessible by the computer device via a network or communication link. For example, data may be retrieved via a modem, via the Internet, or via a local area network. Computer-executable code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, or any suitable combination of the foregoing.

[0051] Computer-readable signal media may include propagated data signals having computer-executable code implemented therein, for example, in baseband or as part of a carrier wave. Such propagated signals may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and is capable of transmitting, propagating, or conveying a program for use by or in connection with an instruction execution system, apparatus, or device.

[0052] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory that a processor can directly access. "Computer storage device" or "storage device" is another example of a computer-readable storage medium. A computer storage device is any non-volatile computer-readable storage medium. In some embodiments, a computer storage device may also be computer memory, or vice versa.

[0053] As used herein, the term "processor" encompasses any electronic component capable of executing programs or machine-executable instructions or computer-executable code. References to computing devices including "processor" should be interpreted as including more than one processor or processing core. A processor may, for example, be a multi-core processor. A processor can also refer to a collection of processors within a single computer system or distributed across multiple computer systems. The term computing device should also be interpreted as potentially referring to a collection or network of computing devices, each including one or more processors. The computer-executable code can be run by multiple processors, which may reside within the same computing device or even be distributed across multiple computing devices.

[0054] Computer executable code may include machine-executable instructions or programs that instruct a processor to perform aspects of the present invention. Computer executable code for performing operations relating to aspects of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages, and compiled into machine-executable instructions. In some cases, the computer executable code may be used in the form of a high-level language or in a pre-compiled form in conjunction with an interpreter that generates machine-executable instructions in flight.

[0055] The computer-executable code can run as a standalone software package entirely on the user's computer, partially on the user's computer, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer via any type of network (including a local area network (LAN) or a wide area network (WAN)) or via a connection to an external computer (e.g., via the Internet using an Internet service provider).

[0056] Various aspects of the present invention are described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block or portion of a block in a flowchart, illustration, and / or block diagram can be implemented, where applicable, by computer program instructions in the form of computer-executable code. It should also be understood that combinations of blocks in different flowcharts, illustrations, and / or block diagrams can be combined when not mutually exclusive. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that instructions executed via the processor of the computer or other programmable data processing apparatus create units for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0057] These computer program instructions may also be stored in a computer-readable medium that can direct a computer, other programmable data processing apparatus or other device to operate in a particular manner, such that the instructions stored in the computer-readable medium produce an article of writing comprising instructions that implement the functions / actions specified in flowcharts and / or one or more block diagrams.

[0058] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer-implemented process, such that the instructions running on the computer or other programmable apparatus provide for implementing the functions / actions specified in the flowchart and / or one or more block diagram boxes.

[0059] As used herein, a "user interface" is an interface that allows a user or operator to interact with a computer or computer system. A "user interface" can also be referred to as a "human-machine interface device." A user interface can provide information or data to an operator and / or receive information or data from an operator. A user interface enables input from an operator to be received by the computer and can provide output from the computer to the user. In other words, a user interface allows an operator to control or manipulate a computer, and the interface allows the computer to indicate the effects of the operator's control or manipulation. The display of data or information on a monitor or graphical user interface is an example of providing information to an operator. Receiving data via a keyboard, mouse, trackball, touchpad, pointing stick, graphics tablet, joystick, gamepad, webcam, helmet, pedal, wired gloves, remote control, and accelerometer are all examples of user interface components that implement the receiving of information or data from an operator.

[0060] As used herein, "hardware interface" encompasses any interface that enables a computer system's processor to interact with or control external computing devices and / or apparatuses. A hardware interface allows the processor to send control signals or instructions to external computing devices and / or apparatuses. A hardware interface also enables the processor to exchange data with external computing devices and / or apparatuses. Examples of hardware interfaces include, but are not limited to: Universal Serial Bus (USB), IEEE 1394 port, parallel port, IEEE 1284 port, serial port, RS-232 port, IEEE-488 port, Bluetooth connectivity, wireless LAN connectivity, TCP / IP connectivity, Ethernet connectivity, control voltage interface, MIDI interface, analog input interface, and digital input interface.

[0061] As used herein, the terms "display" or "display device" encompass output devices or user interfaces suitable for displaying images or data. Displays can output visual, audio, and tactile data. Examples of displays include, but are not limited to: computer monitors, television screens, touchscreens, haptic electronic displays, Braille screens, cathode ray tubes (CRTs), memory tubes, bistable displays, electronic paper, vector displays, flat panel displays, vacuum fluorescent displays (VFs), light-emitting diode (LED) displays, electroluminescent displays (ELDs), plasma display panels (PDPs), liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, projectors, and head-mounted displays.

[0062] Magnetic resonance (MR) data are defined herein as the recorded measurements of radio frequency signals emitted by atomic spins using the antenna of a magnetic resonance imaging (MRI) device during an MRI scan. MRI data is an example of medical imaging data. MRI images, or MR images, are defined herein as reconstructed two-dimensional or three-dimensional visualizations of anatomical data contained within MRI data. Such visualizations can be performed using a computer. Attached Figure Description

[0063] In the following description, preferred embodiments of the invention will be illustrated by way of example only and with reference to the accompanying drawings, in which:

[0064] Figure 1 An example of a medical system is illustrated;

[0065] Figure 2 It is a graphical operation Figure 1 A flowchart illustrating an example of a method for a medical system;

[0066] Figure 3 The diagram shows... Figure 1 Additional components of the medical system;

[0067] Figure 4 The illustrated operation is shown. Figure 4 A flowchart illustrating an example method for a component of the medical system shown.

[0068] Figure 5 This illustration shows another example of a medical system;

[0069] Figure 6 An example of a respiratory phase indicator is shown;

[0070] Figure 7 Another example of a respiratory phase indicator is illustrated; and

[0071] Figure 8 Another example of a respiratory phase indicator is shown.

[0072] List of reference numerals in the attached diagram:

[0073] 100 Medical Systems

[0074] 102 Radiotherapy System

[0075] 104 racks

[0076] 106 Radiation therapy sources

[0077] 108 collimator

[0078] 110 Beam Path

[0079] 112 Irradiation Zone

[0080] 114 Target Volume

[0081] 116 Rotational axis

[0082] 120 Object Support

[0083] 122 Objects

[0084] 124 Ventral region

[0085] 130 monitor

[0086] 130" monitor

[0087] 132 Respiratory Monitoring System

[0088] 132' Respiratory Monitoring System

[0089] 140 Computers

[0090] 142 processor

[0091] 144 Hardware Interfaces

[0092] 146 Memory

[0093] 150 Machine-Executable Instructions

[0094] 152 Time-Resolved Magnetic Resonance Imaging Datasets

[0095] 154 Measuring motion signals

[0096] 156 Expected motion signal

[0097] 156' Expected motion signal in time

[0098] 158 Current motion signal

[0099] 160 Respiratory Phase Indicator

[0100] 160' Respiratory Phase Indicator

[0101] 162 Control Commands

[0102] 200 Time-Resolved Magnetic Resonance Imaging Datasets with Received and Measured Motion Signals Synchronized

[0103] 202 Determining the desired motion signal by measuring the motion signal in time steps

[0104] 204. Use a respiratory monitoring system to collect current motion signals.

[0105] 206. A breathing phase indicator is displayed on the monitor.

[0106] 208 Generate a control command, the control command being configured to control the targeting of the radiotherapy system using either a first portion of a time-resolved magnetic resonance imaging dataset synchronized with the desired motion signal or a second portion of a time-resolved magnetic resonance imaging dataset referenced by the current motion signal.

[0107] 300 Magnetic Resonance Imaging System

[0108] 302 Magnet

[0109] 304 Magnet Chamber

[0110] 306 Imaging Area

[0111] 308 Field of View

[0112] 310 Magnetic Gradient Coil

[0113] 312 Magnetic Gradient Coil Power Supply

[0114] 314 Magnetic Resonance Antenna

[0115] 316 transceiver

[0116] 318 Mirror

[0117] 320 Calibrate Pulse Sequence Command

[0118] 322 Calibration Magnetic Resonance Data

[0119] 324 Motion Phase Separator

[0120] 326 Calibrate motion signals

[0121] 400. Motion signals are acquired and measured using a respiratory monitoring system over a predetermined duration.

[0122] 402. Using calibration pulse sequence commands to control the magnetic resonance imaging system to acquire calibration magnetic resonance data.

[0123] 404 Determining the desired motion signal in time by measuring the motion signal in time steps

[0124] 406. Use a respiratory monitoring system to collect and calibrate motion signals.

[0125] 408. Using calibration motion signals to bin magnetic resonance imaging data into motion phase bins.

[0126] 410 A respiratory phase indicator is displayed on the screen, wherein the respiratory phase indicator is configured to indicate the difference between the motion signal and the calibrated motion signal over time.

[0127] 412 Reconstructing time-resolved magnetic resonance imaging datasets from binned calibration magnetic resonance data

[0128] 500 Medical System

[0129] 502 Low Temperature Thermostat

[0130] 504 superconducting coil

[0131] 600 maximum

[0132] 602 Minimum

[0133] 700 distance Detailed Implementation

[0134] In these figures, similarly numbered elements are equivalent elements or perform the same function. If the functions are equivalent, elements that have been discussed previously will not necessarily be discussed in later figures.

[0135] Figure 1 An example of a medical system 100 is illustrated. Figure 1The medical system 100 includes a radiotherapy system 102. Radiotherapy system 102 is intended to represent one of many different types of radiotherapy systems, such as cobalt radiotherapy systems, X-ray radiotherapy systems, and LINAC. In this example, radiotherapy system 102 includes a gantry 104 with a radiotherapy source 106. A collimator 108 is used to shape the beam path 110. Volume 112 is the irradiation area and represents the volume to which the target volume 114 can be steered. For example, collimator 108 is used to adjust the beam path 110. Gantry 104 has a rotation axis 116 about which the radiotherapy source 106 is rotated.

[0136] The medical system 100 also includes an object support 120 for supporting the object 122. The object support 120 is configured such that it can support the ventral region 124 of the object 122 in the irradiation zone 112.

[0137] The medical system 100 is also shown to include a display 130 and a respiratory monitoring system 132. In this example, the respiratory monitoring system 132 is a camera or infrared camera. Movement of the chest of object 122 can be used to generate motion signals. In this example, there is no high magnetic field, so the type of display 130 is very open. For example, it could be an LCD display, a CRT display, a virtual reality display, or other projection that object 122 can see.

[0138] The radiotherapy system 102, object support 120, display 130, and respiratory monitoring system 132 are all shown as a hardware interface 144 connected to the computer 140. The object support 120 may, for example, include an actuator or motor for adjusting the height and position of the object 122 relative to the rotation axis 116.

[0139] Computer system 140 also includes processor 142. Processor 142 is intended to be representative and may be one or more processor cores within a single computer system 140, or it may be multiple cores and processors distributed across multiple computer systems. Processor 142 is connected to hardware interface 144, which enables processor 142 to control and operate radiotherapy system 102. Processor 142 may optionally be connected to a user interface (not shown). Processor 142 is also shown connected to memory 146. Memory 146 is intended to represent and indicate any combination of memories accessible to processor 142.

[0140] Memory 146 is shown to contain machine-executable instructions 150. These machine-executable instructions enable processor 142 to control the operation and function of the radiotherapy system 102. The machine-executable instructions 150 also enable processor 142 to perform data processing and numerical tasks. Memory 146 is also shown to contain a time-resolved magnetic resonance imaging (MRI) dataset 152. This can be MRI data in its raw form, including four-dimensional MRI data. In other examples, the time-resolved MRI dataset 152 can be preprocessed data, for example, it can indicate the position of organs and various positions of object 122 based on measured motion signals 154.

[0141] The time-resolved magnetic resonance imaging (MRI) dataset 152 references the measured motion signal 154. This means that the time-resolved MRI dataset 152 is also resolved relative to the respiratory phase of the object 122. Although not shown in the figure, the object support 120 may include a radiotherapy table, which may, for example, have constraints or fixations for repeatedly positioning the object 122. The MRI system may also have an equivalent radiotherapy table, also not shown.

[0142] Memory 146 is also shown to include a desired motion signal 156. The desired motion signal 156 is a motion signal determined sequentially by measured motion signals 154 as a function of time. For example, subject 122 may be placed in radiotherapy system 102, and the respiratory phase of subject 122 may be measured by respiratory monitoring system 132 for a short period. After a period of time, processor 142 then synchronizes the measured motion signal 154 with the current motion signal 158 measured by respiratory monitoring system 132. This results in the desired motion signal 156 being generated temporally forward by predicting the current motion signal 158 using the previously measured motion signal 154. Processor 142 may receive the current motion signal 158 from respiratory monitoring system 132. Processor 142 may calculate a respiratory phase indicator 160. The respiratory phase indicator 160 may then be presented on display 130. The respiratory phase indicator 160 may be used to display the difference between the current motion signal 158 and the desired motion signal 156. Memory 146 is also shown to contain control commands 162.

[0143] Control command 162 is used to control the radiotherapy system 102 to irradiate the target volume 114. Control command 162 can be generated in one of two ways. If the current motion signal 158 tracks the desired motion signal 156 well enough, the desired motion signal 156 can be used to predict the future position of the object 122, which can improve the localization of the target volume 114. However, if the current motion signal 158 and the desired motion signal 156 differ too much, the processor 142 can use the current motion signal 158 to determine the target position of the target volume 114. For example, the target can be used by invoking a portion of a time-resolved magnetic resonance imaging dataset 152 corresponding to either the desired motion signal 156 or the closest current motion signal 158.

[0144] Figure 2 The illustrated operation is shown. Figure 1 The flowchart describes a method for a medical system 100. First, in step 200, processor 142 receives a time-resolved magnetic resonance imaging dataset 152 and a measured motion signal 154. Steps 202, 204, 206, and 208 can be repeated cyclically. Next, in step 202, a desired motion signal 156 is determined by stepping through the measured motion signal 154 in time. Then, in step 204, a current motion signal 158 is received from a respiratory monitoring system 132. Then, in step 206, a respiratory phase indicator 160 is determined using the desired motion signal 156 and the current motion signal 158. This indicator is then displayed on a display 130.

[0145] Then, in step 208, control command 162 is generated. This can be accomplished using a first portion of a time-resolved magnetic resonance imaging dataset 152, which corresponds to the time-resolved magnetic resonance imaging dataset 152 and can, for example, be used to register the current position of an object to a radiotherapy plan. Data from the time-resolved magnetic resonance imaging dataset 152 can therefore be used to generate control command 162 by updating the radiotherapy plan.

[0146] Figure 3 Another view of the medical system 100 is shown. Figure 3 The components can be with Figure 1 The components shown are combined. In this sense, the medical system 100 is also shown to include a magnetic resonance imaging system 300.

[0147] The magnetic resonance imaging system 300 includes a magnet 302. The magnet 302 is a superconducting cylindrical magnet with a bore 306 passing through it. Different types of magnets are also possible; for example, split cylindrical magnets and so-called open magnets can also be used. A split cylindrical magnet is similar to a standard cylindrical magnet, except that the cryostat has been split into two parts to allow access to the isoplanar surface of the magnet, thus allowing the magnet to be used, for example, in conjunction with charged particle beam therapy. An open magnet has two magnet sections, one on top of the other, with a space in between large enough to accommodate the object: the arrangement of the two sections is similar to that of a Helmholtz coil. Open magnets are popular because the object is less restricted. An assembly of superconducting coils is located inside the cryostat of the cylindrical magnet.

[0148] Within the bore 306 of the cylindrical magnet 302, there exists an imaging region 306, in which the magnetic field is sufficiently strong and uniform to perform magnetic resonance imaging. The field of view 308 within the imaging region 306 is shown. Acquired magnetic resonance data is typically acquired for the field of view 308. The object 122 is shown supported by an object support 120.

[0149] The magnet's bore 306 also contains an assembly of magnetic field gradient coils 310, used to acquire magnetic resonance data for spatial encoding of magnetic spins within the imaging region 308 of the magnet 302. The magnetic field gradient coils 310 are connected to a magnetic field gradient coil power supply 312. The magnetic field gradient coils 310 are intended to be representative. Typically, the magnetic field gradient coil 310 comprises an assembly of three discrete coils for spatial encoding in three orthogonal spatial directions. The magnetic field gradient power supply supplies current to the magnetic field gradient coils. The current supplied to the magnetic field gradient coils 310 is time-controlled and can be either slanted or pulsed.

[0150] Adjacent to the imaging region 308 is a radio frequency coil 314, which is used to manipulate the orientation of the magnetic spins within the imaging region 308 and to receive radio frequency emissions from spins also within the imaging region 308.

[0151] In this example, the magnetic resonance antenna 314 is shown as a body coil. However, the magnetic resonance antenna 314 is intended to be representative and can be represented by more than one coil or antenna. The radio frequency (RF) antenna may contain multiple coil elements. The RF antenna may also be referred to as a channel or antenna. The RF coil 314 is connected to the RF transceiver 316. The RF coil 314 and the RF transceiver 316 can be replaced by separate transmit and receive coils, as well as separate transmitters and receivers. It is to be understood that the RF coil 314 and the RF transceiver 316 are representative. The RF coil 314 is also intended to represent a dedicated transmit antenna and a dedicated receive antenna. Similarly, the transceiver 316 can also represent separate transmitters and receivers. The RF coil 314 may also have multiple receive / transmit elements, and the RF transceiver 316 may have multiple receive / transmit channels. For example, if performing parallel imaging techniques such as SENSE, the RF coil 314 may have multiple coil elements.

[0152] The magnetic resonance imaging system 300 is shown with an additional respiratory monitoring system 132' and a display 130'. In this example, the display 130' is located outside the aperture 306 and the mirror 318 is positioned such that the object 122 can see the display 130'. This is now shown in the figure, but the object support 120 could be... Figure 1 The support 120 is the same as the top of the radiotherapy bed. This can be used to reproducibly position the object 122 in both the magnetic resonance imaging system 300 and the radiotherapy system 102.

[0153] The radio frequency transmitter 316 and the magnetic field gradient coil power supply 312 are also shown as hardware interfaces 144 connected to the computer system 140.

[0154] Memory 146 is again shown as containing machine-executable instructions. Memory 146 is also shown as additionally containing calibration pulse sequence commands 320, which can be used to control the magnetic resonance imaging system 300 to acquire calibration magnetic resonance data according to a four-dimensional magnetic resonance imaging protocol. Memory 146 is also shown as containing calibration magnetic resonance data 322 acquired by controlling the magnetic resonance imaging system 300 using the calibration pulse sequence commands 320. Memory 146 is also shown as containing measurement motion signals 154 measured using the respiratory monitoring system 132'.

[0155] During the acquisition of calibration MRI data 322, the measured motion signal 154 can be used to divide the calibration MRI data 322 into motion phase bins 324. The time-resolved MRI dataset 152 can then be reconstructed using the k-space MRI data within each motion phase bin 324. A memory 326 is shown containing the calibration motion signal 326. The calibration motion signal 326 is similar to the desired motion signal 154. The calibration motion signal 326 is also reconstructed stepwise from the measured motion signal 154 as a function of time. A memory 146 is shown containing a respiratory phase indicator 160', which is also similar to... Figure 1 The breathing phase indicator is 160.

[0156] Figure 4 The illustrated operation is shown. Figure 3 The flowchart describes a method for using a magnetic resonance imaging (MRI) system 300. First, in step 400, a measured motion signal 154 is acquired using a respiratory monitoring system 132'. Then, in step 412, the MRI system 300 is controlled using a calibration pulse sequence command 320 to acquire MRI data 322. Steps 404, 406, 408, and 410 are repeated during the acquisition of MRI data 322. In step 404, the desired temporal motion signal 156 is determined by stepping through the measured motion signal 154 in time.

[0157] Next, in step 406, a calibration motion signal 326 is acquired using the respiratory monitoring system 132. In step 408, the magnetic resonance imaging data 322 is binned into motion phase bins 324 based on the calibration motion signal 326 or the temporary expected motion signal 156'. In step 410, a respiratory phase indicator 160' is constructed using the calibration motion signal 326 and the temporally expected motion signal 156'. This indicator is then displayed on the display 130'. After performing these steps, the method proceeds to step 412, in which the time-resolved magnetic resonance imaging dataset 152 is reconstructed. It should be noted that some operations, such as binning 408, can be performed after all magnetic resonance imaging data has been acquired.

[0158] Figure 2 and Figure 4 The methods illustrated in the diagram can be combined. For example, you can first execute... Figure 4 The method shown is then executed. Figure 2 The method shown.

[0159] Figure 5 The illustration shows another example of a medical system 500. Figure 5 The examples in the text combine Figure 1 and Figure 3Features illustrated in the diagram. The magnetic resonance imaging system 300 is integrated with the radiotherapy system 102. The radiation zone 112 is within the imaging zone 306. In this example, the radiation beam 110 is shown as passing through a cryostat 502 of the magnet 302. The beam avoids the superconducting coil 504. This is intended to be representative. The magnet 302 could also be replaced with a split coil or an open magnet, so that the radiation beam 110 does not pass through it. Figure 2 and Figure 4 The method shown can also be used for operation Figure 5 The medical system 500. It can be executed first. Figure 4 The method steps, and then can be executed after that. Figure 2 The method steps are illustrated in the diagram. Furthermore, the magnetic resonance imaging system 302 can be used to image the subject 122 during irradiation of the target volume 114. Therefore, the magnetic resonance imaging system 302 can also be used to additionally guide radiotherapy during irradiation.

[0160] Figure 6 An example of a breathing phase indicator 160 is illustrated. The desired motion signal 156 is represented as a repeating waveform. In this example, the maximum breathing phase 600 and minimum 602 are marked and can be used as guidance for the object. The current motion signal 158 is indicated by a cursor. The object attempts to adjust his or her breathing so that the cursor rests on waveform 156.

[0161] Figure 7 An alternative example of the respiratory phase indicator 160 is illustrated. In this example, there are two circles: one circle represents the desired motion signal 156, and the second circle 158 represents the current motion signal. There is a distance of 700 between them, which represents the difference between the current motion signal 158 and the desired motion signal 156.

[0162] Examples can utilize respiratory signals (motion signals 154, 158), acquired by a respiratory monitoring system such as a camera. Personalized biofeedback can be provided to reduce motion artifacts caused by irregular breathing. This can be accomplished by integrating motion substitution or optical motion detection techniques with an environmental in-hole solution to display respiratory signals to the patient to guide their breathing pattern. Therefore, acquiring more accurate and faster 4D MRI images for treatment planning purposes is feasible. Furthermore, respiratory signals acquired via optical detection systems can be used as personalized biofeedback during treatment to maintain a breathing pattern similar to that of a simulated session, resulting in better treatment.

[0163] To enable accurate treatment planning in the presence of respiratory motion, 4D CT imaging has been used clinically to characterize respiratory motion in tumors and organs at risk (OARs) to minimize radiotoxicity to healthy tissues and maximize radiotoxicity to tumors during radiotherapy. Over the past decade, 4D MRI technology has been developed to overcome the limitations of 4D CT, such as lack of soft tissue contrast and excessive ionizing radiation.

[0164] Amplitude-based 4D MRI can be provided to acquire T2-weighted single-shot fast spin-echo (TSE) images during the definition phase of the respiratory cycle using common respiratory substitutes (respiratory monitoring system 132): internal navigator or external bellows. Because this 4D MRI technique is based on amplitude-prospective triggering, long acquisition times are reported due to repeated pauses caused by highly irregular breathing patterns. Furthermore, irregular breathing patterns, very common in patients with cancer, can lead to misclassification of respiratory phases, resulting in binning artifacts (aka motion artifacts) and discontinuities in patient anatomy in the 4D MRI images. In some examples, prospective 4D MRI can use an initial 10-second training cycle, where the program learns patient-specific respiratory parameters and uses them to establish binning levels for subsequent image acquisition. While this aids in 4D MRI acquisition, it assumes that the next 6–10 minutes of breathing will follow the training behavior. Therefore, respiratory irregularities with large respiratory amplitudes will be ignored. This does not necessarily result in any motion artifacts, but will not faithfully represent the patient's respiratory behavior. In other words, if 4D MRI simulation is applied to tumor motion assessment, it may underestimate irregularities. Therefore, 4D MRI suffers from the drawbacks of 4D CT because the underlying respiratory-related approaches do not include mechanisms for incorporating respiratory irregularity information into 4D MRI. Audio guidance and visual biofeedback can be combined with 4D MRI acquisition and radiotherapy to improve respiratory regularity, increase anatomical reproducibility, and reduce the overall time burden of these procedures.

[0165] Using internal navigators and external bellows as alternatives to 4D MRI has several limitations. For external bellows, signal saturation, gain reset, logistics during setup and positioning time, battery life, and MR chamber interference are some of the limitations. Internal navigators have been shown to provide more accurate signals than external bellows, but obtaining strong internal navigator signals is difficult because performance depends on operator expertise in navigator planning and internal organ motion. Furthermore, if the navigator overlaps with the imaging slice, it can cause imaging interruptions and potentially lead to saturation of the imaging volume. As a common problem with both internal navigators and external bellows, the quality of the alternative signal can significantly affect the expected phase sequencing of 4D MRI, resulting in motion artifacts. Motion artifacts have been reported to cause changes in gross tumor volume (GTV) of up to 110% during respiratory cycles in lung cancer 4D CT, and the internal tumor volume (ITV) increases several times when considering tumor motion trajectories. By using better respiratory alternatives to minimize 4D MRI motion artifacts, the uncertainty of GTV is expected to be reduced.

[0166] Examples could include a camera that detects motion at the center of the scanner (within the bore 306 of magnet 302). This motion is analyzed and converted into a respiratory signal (motion signals 154, 158). This can be integrated into 4D MR technology to eliminate the limitations of internal navigator or external bellows signals. This system may be more robust and accurate than respiratory bellows signals. Furthermore, it is a non-interactive optical system that requires no operator or patient intervention.

[0167] Current biofeedback systems (respiratory phase indicator 160) have limitations. In some examples, the respiratory waveforms (motion signals 154, 158) used for 4D MRI triggering and biofeedback are derived using two different external surrogates. While both waveforms are based on abdominal movement, ideally, these two systems would be integrated. Simple biofeedback signals (e.g., LED displays) may not be optimally representative of a patient's respiratory waveform. Ideally, the patient's respiratory waveform used for phase classification in 4D MRI technology could also be used as a biofeedback signal.

[0168] A better solution might be to use an intrathoracic solution where the integrated visual effects (respiratory phase indicator 160) can be displayed on the posterior wall and seen through a mirror 318 on the head coil, while the patient 122 can listen to music / sounds played through headphones. Here, we propose displaying the respiratory signals obtained by imaging the patient via an optical system as personalized visual biofeedback to guide the patient's breathing patterns.

[0169] Examples may include one or more of the following characteristics:

[0170] 1. Integrated motion substitution or optical technology for 4D MRI to achieve more accurate respiratory substitution, addressing current issues with internal and external substitution.

[0171] 2. Utilize respiratory signals obtained through motion substitution techniques or optical systems as personalized biofeedback to reduce motion artifacts caused by irregular breathing. This can be accomplished by combining motion substitution techniques, such as optical technologies, with environment-to-intracorporeal solutions to display respiratory signals to the patient to guide their breathing patterns.

[0172] By integrating the optical respiratory monitoring system 132 into a 4D MRI system, more robust and accurate respiratory substitution signals (motion signals 154, 158) can be obtained. This accurate substitution facilitates more reliable phase classification in 4D MRI. Furthermore, it helps reduce idle time in 4D MRI technology, utilizes more robust substitutions, and ultimately reduces scan time.

[0173] An example could provide an intra-canal solution (for MRI magnet 302) where the visual effect of the engagement can be displayed on the posterior wall and seen through a mirror on the head coil, while the patient can listen to music / sound through headphones. Here, we suggest displaying the respiratory signal used in 4D MRI acquired via an optical system or camera to the patient as personalized visual biofeedback to guide the patient's breathing pattern. The end-inspiratory range 602 and end-expiratory range 600 can be displayed on a wall-mounted monitor to guide the patient's breathing within the lines, maintaining a constant range of respiratory signal amplitude. This helps achieve a regular breathing pattern, contributing to the acquisition of better quality, more accurate phase-classified 4D MRI images and reducing motion artifacts. Furthermore, scan time will be reduced due to the regular breathing pattern. This is discussed below. Figure 8 This was explained in the text.

[0174] Figure 8 This refers to object 122 within the chamber of the medical system. For example... Figure 6 As shown, a breathing phase indicator 160 is projected on the wall. Mirror 318 allows object 122 to see it.

[0175] Figure 8 The figure depicts a respiratory monitoring system 132 that uses an infrared camera to acquire robust respiratory signals for use as a respiratory surrogate in 4D MRI. The figure provides a schematic diagram of how to display the respiratory signals acquired by the infrared camera in real time on a wall using an intra-canal solution. Lines 600 and 602 can be used to guide the patient's breathing within this range to maintain a constant respiratory amplitude.

[0176] In addition to acquiring more accurate and faster 4D MRI images, respiratory signals obtained from infrared cameras can be stored for use as personalized biofeedback during treatment to maintain a similar breathing pattern and amplitude to the simulated session when 4D MRI images are acquired and used for treatment planning.

[0177] Examples may be useful for radiotherapy (RT) simulations of any anatomical structures affected by respiratory motion, particularly the upper abdomen (liver, pancreas) and chest (lungs, esophagus), and are also applicable to MR LINAC, CT simulations, or LINAC.

[0178] Although the invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary, and not restrictive. The invention is not limited to the disclosed embodiments.

[0179] Those skilled in the art, through studying the accompanying drawings, disclosure, and claims, will understand and implement other variations of the disclosed embodiments when practicing the claimed invention. In the claims, the word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude a plurality. A single processor or other unit can perform the functions of several items recited in the claims. Although specific measures are recited in dissimilar dependent claims, this does not imply that combinations of these measures cannot be advantageously used. Computer programs can be stored / distributed on suitable media such as optical storage media or solid-state media provided with or as part of other hardware, but can also be distributed in other forms such as via the Internet or other wired or wireless telecommunications systems. Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. A medical system (100, 500), comprising: Magnetic resonance imaging system (302), A radiotherapy system (102) configured to controllably irradiate a target volume (114) within an irradiation zone (112); An object support (120) is configured to support at least the ventral region (124) of the object (122) within the irradiation zone; A respiratory monitoring system (132, 132') is configured to provide motion signals (154, 158) describing the respiratory movements of an object; An object display (130, 130') is configured to display a breathing phase indicator (160, 160') to the object when supported by the object support. A memory (146) storing machine-executable instructions (150), wherein the memory further includes a calibration pulse sequence command (320) configured to acquire calibration magnetic resonance data (322) from an imaging region (306) according to a four-dimensional magnetic resonance imaging protocol; and A processor (142) for controlling the medical system; The execution of the machine-executable instructions enables the processor to: The respiratory monitoring system is used to acquire (400) measured motion signals over a predetermined duration; and The calibration pulse sequence command is used to control (402) the magnetic resonance imaging system to acquire the calibration magnetic resonance data, wherein the calibration magnetic resonance data is divided into motion phase bins; The execution of the machine-executable commands also causes the processor to repeatedly perform the following operations during the acquisition of the calibration magnetic resonance data: The desired motion signal in time (156') is determined by stepping through the measured motion signal in time (404); The respiratory monitoring system is used to collect (406) calibration motion signals (326); The magnetic resonance imaging data is binned (408) into the motion phase bin using the calibration motion signal, and The breathing phase indicator (160') is presented (410) on the object display, wherein the breathing phase indicator is configured to indicate the difference between the desired motion signal and the calibrated motion signal over the time. The execution of the machine-executable instructions also enables the processor to reconstruct (412) a time-resolved magnetic resonance imaging dataset (152) based on the calibrated magnetic resonance data; The execution of the machine-executable instructions also causes the processor to repeatedly: The desired motion signal (156) is determined by stepping through the measured motion signal in time (202); The respiratory monitoring system is used to collect (204) current motion signals (158); The breathing phase indicator is presented (206) on the object display, wherein the breathing phase indicator is configured to indicate the difference (700) between the desired motion signal and the current motion signal; and A control command (162) is generated (208) and configured to control the targeting of the radiotherapy system using a first portion of a time-resolved magnetic resonance imaging dataset synchronized with the desired motion signal or a second portion of the time-resolved magnetic resonance imaging dataset referenced by the current motion signal, wherein the control command is configured to select between the first portion and the second portion of the time-resolved magnetic resonance imaging dataset by applying predetermined criteria to the matching between the current motion signal and the measured motion signal.

2. The medical system according to claim 1, wherein, The magnetic resonance imaging system is integrated into the radiotherapy system, wherein the irradiation area is within the imaging area.

3. The medical system according to claim 2, wherein, The memory also contains imaging pulse sequence commands, wherein the execution of the machine-executable instructions further enables the processor to: During the generation of the control command, the magnetic resonance imaging system is controlled using the imaging pulse sequence command to acquire imaging magnetic resonance data; and At least one magnetic resonance image is reconstructed based on the imaging magnetic resonance data, wherein the respiratory phase indicator is also configured to display the at least one magnetic resonance image.

4. The medical system according to claim 2, wherein, The irradiated area and the imaging area do not intersect.

5. The medical system according to any one of claims 1-4, wherein, The breathing phase indicator is configured to display the desired motion signal as a waveform, wherein the breathing phase indicator is further configured to display the current motion signal as a position relative to the waveform.

6. The medical system according to any one of claims 1-4, wherein, The breathing phase indicator is configured to display the desired motion signal as the location of a first object, wherein the breathing phase indicator is also configured to display the current motion signal as the location of a second object.

7. The medical system according to any one of claims 1-4, wherein, The breathing phase indicator is configured to control the animation of an object using the desired motion signal and the current motion signal.

8. The medical system according to any one of claims 1-4, wherein, The execution of the machine-executable instructions also enables the processor to control the radiotherapy system using the control commands.

9. The medical system according to any one of claims 1-4, wherein, The respiratory monitoring system includes any of the following: a breathing belt, an optical respiratory detection system, an infrared respiratory detection system, an internal navigator pulse sequence, and combinations thereof.

10. The medical system according to any one of claims 1-4, wherein, The object display is any of the following: a projector configured to project a respiratory phase indicator onto a wall, a projector configured to project a respiratory phase indicator onto the cavity of a medical system, an LCD display, and a magnetic resonance imaging compatible display.

11. The medical system according to any one of claims 1-4, wherein, The radiotherapy system is any of the following: a linear accelerator radiotherapy system, a cobalt radiotherapy system, or an X-ray radiotherapy system.

12. A method for operating a medical system (100, 500), wherein, The medical system includes: Magnetic resonance imaging system (302), A radiotherapy system (102) configured to controllably irradiate a target volume (114) within an irradiation zone (112); An object support (120) is configured to support at least the ventral region (124) of the object within the irradiation zone; A respiratory monitoring system (132, 132') configured to provide motion signals (154, 158) describing the respiratory movements of a subject; and An object display (308, 308') is configured to display a breathing phase indicator (160, 160') to an object supported by the object support. The method includes: The respiratory monitoring system is used to acquire (400) measured motion signals over a predetermined duration; and The magnetic resonance imaging system is controlled (402) to acquire calibration magnetic resonance data using a calibration pulse sequence command, wherein the calibration pulse sequence command (320) is configured to acquire calibration magnetic resonance data (322) from the imaging region (306) according to a four-dimensional magnetic resonance imaging protocol, wherein the irradiation region is within the imaging region, and wherein the calibration magnetic resonance data is divided into motion phase bins. The method further includes repeatedly performing the following operations: The desired motion signal in time (156') is determined by stepping through the measured motion signal in time (404); The respiratory monitoring system is used to collect (406) calibration motion signals (326); The magnetic resonance imaging data bins (408) are assigned to the motion phase bins using the calibration motion signal, and The breathing phase indicator (160') is presented (410) on the object display, wherein the breathing phase indicator is configured to indicate the difference between the desired motion signal and the calibrated motion signal over the time. The method further includes reconstructing (412) a time-resolved magnetic resonance imaging dataset (152) based on the calibrated magnetic resonance data; The method further includes repeatedly performing the following operations: The desired motion signal (156) is determined by stepping through the measured motion signal in time (202); The respiratory monitoring system is used to collect (204) the current motion signal (158); A respiratory phase indicator (206) is presented on the object display, wherein the respiratory phase indicator is configured to indicate the difference (700) between the desired motion signal and the current motion signal; and A control command (162) is generated (208) and configured to control the targeting of the radiotherapy system using a first portion of a time-resolved magnetic resonance imaging dataset synchronized with the desired motion signal or a second portion of a time-resolved magnetic resonance imaging dataset referenced by the current motion signal, wherein the control command selects between the first portion and the second portion of the time-resolved magnetic resonance imaging dataset by applying predetermined criteria to the matching between the current motion signal and the measured motion signal.

13. A computer program product comprising instructions for causing a medical system according to claim 1 to perform the steps of the method according to claim 12.

Images